1 // Copyright 2023 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "components/metrics/persistent_synthetic_trial_observer.h"
6
7 #include "base/task/sequenced_task_runner.h"
8 #include "components/metrics/persistent_system_profile.h"
9 #include "components/variations/synthetic_trials.h"
10
11 namespace metrics {
12 namespace {
13
PersistSyntheticFieldTrials(const std::vector<variations::SyntheticTrialGroup> & trials_updated,const std::vector<variations::SyntheticTrialGroup> & trials_removed)14 void PersistSyntheticFieldTrials(
15 const std::vector<variations::SyntheticTrialGroup>& trials_updated,
16 const std::vector<variations::SyntheticTrialGroup>& trials_removed) {
17 // Mark all the updated synthetic field trials in the persistent profile,
18 // update the removed trials first, then add the updated trials.
19 // TODO: crbug.com/345445618 - Handle kNextLog annotation mode properly, and
20 // when the annotation mode changes.
21 for (const auto& removed : trials_removed) {
22 metrics::GlobalPersistentSystemProfile::GetInstance()->RemoveFieldTrial(
23 removed.trial_name());
24 }
25 for (const auto& updated : trials_updated) {
26 if (updated.annotation_mode() ==
27 variations::SyntheticTrialAnnotationMode::kCurrentLog) {
28 metrics::GlobalPersistentSystemProfile::GetInstance()->AddFieldTrial(
29 updated.trial_name(), updated.group_name());
30 }
31 }
32 }
33
34 } // namespace
35
PersistentSyntheticTrialObserver()36 PersistentSyntheticTrialObserver::PersistentSyntheticTrialObserver()
37 : task_runner_(base::SequencedTaskRunner::GetCurrentDefault()) {}
38
39 PersistentSyntheticTrialObserver::~PersistentSyntheticTrialObserver() = default;
40
OnSyntheticTrialsChanged(const std::vector<variations::SyntheticTrialGroup> & trials_updated,const std::vector<variations::SyntheticTrialGroup> & trials_removed,const std::vector<variations::SyntheticTrialGroup> & groups)41 void PersistentSyntheticTrialObserver::OnSyntheticTrialsChanged(
42 const std::vector<variations::SyntheticTrialGroup>& trials_updated,
43 const std::vector<variations::SyntheticTrialGroup>& trials_removed,
44 const std::vector<variations::SyntheticTrialGroup>& groups) {
45 // Synthetic trials may be registered in any task runner, so switch to correct
46 // task runner before storing.
47 if (task_runner_->RunsTasksInCurrentSequence()) {
48 PersistSyntheticFieldTrials(trials_updated, trials_removed);
49 } else {
50 task_runner_->PostTask(
51 FROM_HERE, base::BindOnce(&PersistSyntheticFieldTrials, trials_updated,
52 trials_removed));
53 }
54 }
55
56 } // namespace metrics
57